Add ru version (#1865)

* Add Russian docs site baseline

* Add Russian localized codebase

* Polish Russian code wording

* Update ru code translation.

* Update code translation and chapter covers.

* Fix pythontutor extraction.

* Add README and landing page.

* placeholder of profiles

* Use figures of English version

* Remove chapter paperbook

ru/codes/dart/utils/list_node.dart

@@ -0,0 +1,24 @@
+/**
+ * File: list_node.dart
+ * Created Time: 2023-01-23
+ * Author: Jefferson (JeffersonHuang77@gmail.com)
+ */
+
+/* Узел связного списка */
+class ListNode {
+  int val;
+  ListNode? next;
+
+  ListNode(this.val, [this.next]);
+}
+
+/* Десериализовать список в связный список */
+ListNode? listToLinkedList(List<int> list) {
+  ListNode dum = ListNode(0);
+  ListNode? head = dum;
+  for (int val in list) {
+    head?.next = ListNode(val);
+    head = head?.next;
+  }
+  return dum.next;
+}